This might be a bit long. I had the codes P0155, P0135, and P047 on for about a year or so. Every once in a while the check engine light would pop off by itself and then re-appear. I have cleared the codes a few times and be ok for a few days then they will pop back on. Always figured I would get to it later since the o2 sensors didn't seem to be affecting the engine or fuel economy. Well now time is up. I had state inspection, figured I would just clear the codes before I went and would be golden until summer when its warm out to fix it. Well now I know that they automatically fail the car if you do that. Whats worse is I have until the end of the month to pass or I cannot renew my registration. In NJ its a big deal to not have registration, big fine, not sure about insurance and they impound the car.

From searching I was hoping it was going to be a fuse or a bad wire. I was not sure what fuse it was so I checked all the 15 amp fuses in the relay center and they came up ok. I have not looked at the wires. I am getting .44 volts to all 3 sensors (info from my scanner). I tried reseting the drive cycle for OBDII today and while I was on step 3 the CE light popped up again so I aborted the rest of the test. When I got home I am only getting P0147.

If I need sensors I need to order them ASAP or I cannot legally drive to work. Also from searching it seems like doing the "GM drive cycle" will not reset the computer, is this true? This is on a 2000 Jimmy btw. I havent been here in a while so not sure if its in the sig or not.

Thanks for any info.

 

Maybe a dumb question - How can they tell that you cleared the codes?

I hate government. One good thing I can say about Indiana, is that they did away with vehicle inspections waaaay back, around 1975-1980.

 

When you clear the codes it wipes out all data and the system isnt ready to be "tested". I knew that happens when you disconnect the battery but figured if I cleared them with the scanner it would just clear the CE light. [sm=nono.gif]
When I checked the code after inspection I was digging around for info from the scanner and the scanner told me it was 20 miles since I cleared the codes.

 

Clearing codes and resetting the PCM are one in the same as you have found out. You cannot just clear the codes hoping to pass your inspection as the problem is still there.

P0135 - HO2S Heater Circuit Bank 1 Sensor 1
P0147 - HO2S Heater Circuit Bank 1 Sensor 3
P0155 - HO2S Heater Circuit Bank 2 Sensor 1

I highly doubt that all three of your oxygen sensors have crapped out all at once.

I would suspect a faulty ground circuit. B1S1 gets its ground from the back of the driver side cylinder head while B2S1 & B1S3 get their ground from a bolt on the back of the passenger side cylinder head. You could test the resistance between the ground pin on the O2 sensor plug and ground. You may also want to test for proper voltage at the heater +12V supply pin.

The B1S3 (sometimes referred to as B1S2 as well in the 98+) sensor voltage should stay relatively constant, however, B1S1 and B2S1 voltages should bounce around between ~100mV and ~900mV as the PCM modifies the A/F ratio.

 

anyone know the part numbers for the sensors? According to AC Delco's site it only lists 2 and are pre and post cat with the same part numbers? I know this is not right because the front ones are different than the rear cat sensor.

Thanks

http://parts-catalog.acdelco.com/b2c/catalog_search.php

edit: the link doesnt show the right page.

 

nevermind, I am wrong once again, same sensor for all 3. I am going to try to replace sensor 3 and see what pops up after that.

Update: I changed out P0135 and that code went away so I changed out the other 2. The P0147 popped back up. I plan on switching them out to see if the sensor is bad or if something else is wrong. (cat or wiring?)

 

I got around to swapping out the sensors on Saturday. While I had them off I checked the grounds at the connector, I could not get the grounds at the heads. I also re-checked the 20 amp O2 fuse and it was blown. I replaced it and put the rest of the car back together. About 2 minutes after starting the car the SES light went off so I reset the PCM to get rid of the old code and was waiting for a ready conditon. I also rechecked the fuse after I drove around it was still good. Last night on my way to work the SES popped back up with the same code P0147. I checked the fuse and it was blown.

Is there a common place for this sensor to short? I looked at the harness as far back as I could get to and couldn't see anything wrong with it.

Thanks for any help. I was able to register right after I failed but I am still able to get the $150+ no inspection ticket.

I also wanted to say thanks to swartlkk for the help in this thread and others that he helped in. I have been searching and he pointed me in the right direction to get me this far.

Also as a side note incase someone searches for help I struggled to get one of the sensors off with the O2 socket I picked up a few years ago. Tried a can of PB blaster and a torch for roughly an hour and got nowhere. Grabbed a 22mm wrench when I did the other 2 and changed both in 20 minutes.

 

I would test each heater power feed for continuity to ground. See what that turns up.

As far as common places for things to ground out... Never have seen a common place. It may be inside the wiring harness all together...

 

ok, I have a ground somewhere on the pink wire (looks red to me but I am on my back with a flashlight) that leads to the fuse center, routes to all 3 sensors. I do not understand why all 3 of them are not coding?
Going back out now that I know that this wire connects to all the sensors to check the other harnesses. Hopefully there is something right in the open.

 

It is possible that something inside the B1S3 sensor is causing the problem. You say that you got the sensors off. Does this mean that you have replaced them?

What happens if you disconnect the B1S3 sensor and drive it around? Will the fuse still blow?